U.S. patent number 8,231,607 [Application Number 12/381,260] was granted by the patent office on 2012-07-31 for suction catheter and suction-catheter system.
Invention is credited to Norikata Takuma.
United States Patent |
8,231,607 |
Takuma |
July 31, 2012 |
Suction catheter and suction-catheter system
Abstract
Provided is a suction catheter including: a catheter main body
made of a flexible lengthy body having a lumen inside; a
leading-end case portion positioned at a leading-end portion of the
catheter main body and including an opening for retrieving an
object; and object cutting means partially exposed through the
opening and movable in the axial direction within the leading-end
case portion. The object cutting means includes a cutting portion
exposed through the opening portion, and a power receiving portion
driving the cutting portion when receiving power from outside. A
leading-end side of the suction catheter is inserted into a blood
vessel while a base-end portion of the suction catheter is
connected to a suction apparatus. An object sticking to the
internal wall of the blood vessel is cut off by operating the
object cutting means in the opening of the leading-end case portion
while the lumen is vacuumed. The cut-off object is immediately
sucked in and retrieved.
Inventors: |
Takuma; Norikata (Kokubunji,
JP) |
Family
ID: |
40785233 |
Appl.
No.: |
12/381,260 |
Filed: |
March 10, 2009 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20100016785 A1 |
Jan 21, 2010 |
|
Foreign Application Priority Data
|
|
|
|
|
Jul 18, 2008 [JP] |
|
|
2008-186974 |
|
Current U.S.
Class: |
604/540; 604/128;
604/508; 604/266 |
Current CPC
Class: |
A61B
17/22004 (20130101); A61B 17/320783 (20130101); A61B
2017/320008 (20130101); A61B 2017/22079 (20130101); A61B
2017/00876 (20130101); A61B 2017/32004 (20130101); A61B
2017/00398 (20130101) |
Current International
Class: |
A61M
1/00 (20060101) |
Field of
Search: |
;604/540,128-129,266-268,508-510 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
9-192230 |
|
Jul 1997 |
|
JP |
|
2000-279525 |
|
Oct 2000 |
|
JP |
|
2005-95410 |
|
Apr 2005 |
|
JP |
|
2006-263125 |
|
Oct 2006 |
|
JP |
|
2006-271693 |
|
Oct 2006 |
|
JP |
|
2008-23318 |
|
Feb 2008 |
|
JP |
|
2008-513111 |
|
May 2008 |
|
JP |
|
Primary Examiner: Anderson; Lynne
Attorney, Agent or Firm: Jordan and Hamburg LLP
Claims
What is claimed is:
1. A suction catheter made of a flexible lengthy body with a lumen
formed therein, and used in a treatment where a leading-end side of
the suction catheter is adapted to be inserted into a blood vessel,
where a base-end portion is connected to a suction apparatus, and
where the lumen is vacuumed by means of the suction apparatus
adapted to suck out and retrieve an object in the blood vessel, the
suction catheter comprising: a catheter main body made of the
flexible lengthy body; a leading-end case portion positioned at a
leading-end portion of the catheter main body and including an
opening for retrieving the object; and object cutting means that is
partially exposed through the opening, and is movable in the axial
direction within the leading-end case portion, wherein the object
cutting means includes: a cutting portion with a cutting area made
of a wire-like member provided so as to traverse in a substantially
perpendicular direction to the axial direction; a power receiving
portion that is connected to the cutting portion, and moves the
cutting portion in the axial direction when the power receiving
portion receives power from outside, and while the object cutting
means is in operation, the object that sticks to an internal wall
of the blood vessel is cut off, at the opening of the leading-end
case portion, by means of the cutting area of the cutting
portion.
2. The suction catheter according to claim 1, wherein the cutting
portion is a spiral body formed by winding up the wire-like member
a number of times.
3. The suction catheter according to claim 1 or 2, wherein the
leading-end case portion includes a locking stopper formed in an
internal wall of the leading-end case portion, the locking stopper
restricting a movement of the object cutting means toward the
base-end portion of the catheter main body.
4. The suction catheter according to claim 1 or 2, wherein any one
of at least a part of the leading-end case portion and at least a
part of the object cutting means is made of a metal member.
5. The suction catheter according to claim 1 or 2, wherein the
opening is formed in a leading-end inclined face of an
obliquely-formed leading-end portion of the leading-end case
portion.
6. The suction catheter according to claim 1 or 2, wherein the
opening is formed in a leading-end-side circumferential-body
surface of the leading-end case portion.
7. The suction catheter according to claim 1 or 2, wherein at least
one of the catheter main body and the leading-end case portion
includes a guide-wire hole formed in the outer surface thereof, the
guide-wire hole allowing a guide wire to be inserted thereinto.
8. A suction-catheter system comprising: the suction catheter
according to claim 1 or 2; and driving means for supplying power to
the object cutting means included in the suction catheter.
9. The suction-catheter system according to claim 8, wherein the
driving means is capable of adjusting the strength of the power
supplied to the object cutting means.
10. The suction-catheter system according to claim 8, wherein the
object cutting means includes a stretchable member that enables the
object cutting means to move back and forth in response to the
change in the strength of the power supplied by the driving means,
and the driving means is a suction apparatus that attracts the
object cutting means by means of a sucking force.
11. The suction catheter according to claim 1, wherein the
leading-end case portion has a wall extending from a proximal end
to a distal end, wherein said opening extends distally along the
wall, and wherein the cutting portion is exposed through the
opening and remains at least partially within the leading-end case
portion during axial movement during a cutting operation so that
suction and cutting occur concurrently on the object within the
opening.
12. The suction catheter according to claim 1, wherein the
leading-end case portion has an inclined face, and wherein said
opening extends along the inclined face proximal to a distal tip of
the leading-end case portion.
13. The suction catheter according to claim 12, wherein the cutting
portion is anchored to a distal end of the leading-case portion
during a cutting operation.
14. The suction catheter according to claim 1, wherein the cutting
portion moves axially within the leading-end case portion during a
cutting operation between a first configuration in which the
cutting portion spans a first length within the opening proximal to
the distal end and a second configuration in which the cutting
portion spans a second length, greater than the first length,
within the opening proximal to the distal end.
15. The suction catheter according to claim 1, wherein the object
cutting means has a first end at which is the cutting portion and a
second end at which is the power receiving portion, wherein both
the cutting portion and power receiving portion are situated in the
leading-end case portion, an entirety of the leading-end portion
adapted to be inserted inside the blood vessel.
16. The suction catheter according to claim 1, wherein the cutting
portion is positioned within the opening and is adapted to cut a
portion of the object within the path of the cutting portion within
the opening during a cutting operation so that cutting of the
object and suctioning to retrieve a cut portion of the object occur
concurrently within at least a volume within the leading-end case
portion bordered by a plane of the opening.
17. A suction catheter made of a flexible lengthy body with a lumen
formed therein, and used in a treatment where a leading-end side of
the suction catheter is adapted to be inserted into a blood vessel,
where a base-end portion is connected to a suction apparatus, and
where the lumen is vacuumed by means of the suction apparatus
adapted to suck out and retrieve an object in the blood vessel, the
suction catheter comprising: a catheter main body made of the
flexible lengthy body; a leading-end case portion positioned at a
leading-end portion of the catheter main body and including an
opening for retrieving the object; and object cutting means that is
partially exposed through the opening, and is movable in the axial
direction within the leading-end case portion, wherein the object
cutting means includes: a cutting portion with a cutting area made
of a wire-like member provided so as to traverse in a substantially
perpendicular direction to the axial direction; a power receiving
portion that is connected to the cutting portion, and moves the
cutting portion in the axial direction when the power receiving
portion receives power from outside, and while the object cutting
means is in operation, the object that sticks to an internal wall
of the blood vessel is cut off, at the opening of the leading-end
case portion, by means of the cutting area of the cutting portion;
and wherein the power receiving portion is made of a magnetic
material, and the leading-end case portion includes magnetic-force
generating means for supplying power to the power receiving
portion, the magnetic-force generating means being provided to the
internal wall of the leading-end case portion.
18. The suction catheter according to claim 17, wherein the cutting
portion is a spiral body formed by winding up the wire-like member
a number of times.
19. A suction-catheter system comprising a suction catheter and a
driving means, the suction catheter made of a flexible lengthy body
with a lumen formed therein, and used in a treatment where a
leading-end side of the suction catheter is adapted to be inserted
into a blood vessel, where a base-end portion is connected to a
suction apparatus, and where the lumen is vacuumed by means of the
suction apparatus adapted to suck out and retrieve an object in the
blood vessel, the suction catheter comprising: a catheter main body
made of the flexible lengthy body; a leading-end case portion
positioned at a leading-end portion of the catheter main body and
including an opening for retrieving the object; and object cutting
means that is partially exposed through the opening, and is movable
in the axial direction within the leading-end case portion, wherein
the object cutting means includes: a cutting portion with a cutting
area made of a wire-like member provided so as to traverse in a
substantially perpendicular direction to the axial direction; a
power receiving portion that is connected to the cutting portion,
and moves the cutting portion in the axial direction when the power
receiving portion receives power from outside, and while the object
cutting means is in operation, the object that sticks to an
internal wall of the blood vessel is cut off, at the opening of the
leading-end case portion, by means of the cutting area of the
cutting portion; wherein the driving means supplies power to the
object cutting means included in the suction catheter; and wherein
at least a part of the object cutting means is made of a magnetic
material, and the driving means is a magnetic-force apparatus that
attracts or repels the object cutting means by means of a magnetic
force.
20. The suction catheter according to claim 19, wherein the cutting
portion is a spiral body formed by winding up the wire-like member
a number of times.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a suction catheter used in a
treatment where the suction catheter is inserted into a blood
vessel to suck out and remove an object such as a blood clot
therefrom. Specifically, the present invention relates to a
technique that is used when objects cause an occluded
blood-vascular system, such as in the case of cerebral infarction
or myocardial infarction, for the purpose of retrieving and
removing the objects, easily and smoothly, from the blood vessel
without allowing the objects to flow down the stream.
2. Description of the Related Art
A number of diseases are known to be caused by an occluded blood
vessel. For example, each of the cerebral infarction and the
myocardial infarction is a disease caused by an occluded arterial
system of the corresponding organ. An economy-class syndrome is a
potentially fatal disease that is caused by an occluded pulmonary
blood vessel due to a blood clot formed in a leg vein.
The blood clot formed in a blood vessel is conventionally removed
by use of an apparatus inserted into the blood vessel mainly in
accordance with any one of the following two known methods. In one
method, an object, such as a blood clot, is removed by being sucked
out with the opening at the leading end of the suction catheter
being brought into direct contact with the object. In the other
method, the blood clot is firstly fractured, and the fractured
fragments of the blood clot are then sucked out by the suction
catheter.
For example, the following techniques have been proposed. A suction
catheter employed in a proposed technique includes: a catheter main
body to be inserted into the blood vessel; and a vibrator that
makes the catheter main body vibrate. The vibrating catheter main
body is brought into contact with a blood clot, and thus the blood
clot is gradually fractured from the surface. According to this
technique, the blood clot can be quickly removed without damaging
the blood vessel. For more detail, see Japanese Patent Application
Publication No. 2005-95410 (Patent Document 1).
A suction catheter employed in another proposed technique includes
an actuator provided near the leading end of the catheter. When the
actuator is made to vibrate, the vibration in turn makes the
leading end of the catheter vibrate. The leading end of the
vibrating catheter or an irregular face formed at the leading end
is used for chipping away the adjacent objects. For more detail,
see Japanese Patent Application Publication No. Hei 9-192230
(Patent Document 2).
FIG. 13 shows a suction catheter 100 employed in still another
proposed technique. The suction catheter 100 includes an
obliquely-formed leading-end portion 101a. The leading-end portion
101a is brought into contact with the object, such as a blood clot,
while the inside of a lumen 111 of a catheter main body 101 is
being vacuumed. Thus, the object is removed by the sucking force.
An example of the suction catheter of this type is a blood-clot
suction catheter that is commercially available under the
registered trade name Thrombuster from Kaneka Medix Corp. Another
example of the type of suction catheter is a catheter for removing
embolus in the central circulatory system that is commercially
available under the registered trade name Eliminate from Clinical
Supply Co., Ltd.
A suction catheter employed in still another proposed technique
includes a taper-shaped spiral portion provided at a leading-end
portion of the suction catheter main body. The spiral portion has a
coil-shaped piece wound up by at least one turn. A catheter for
fracturing objects is disposed inside the spiral portion, and
ejects a jet stream of a liquid to fracture an object (for example,
a blood clot) in the blood vessel. The object thus fractured is
then sucked up from the leading-end portion of the catheter, and is
taken to the outside. For more detail, see Japanese Patent
Application Publication No. Hei 2006-271693 (Patent Document
3).
A suction catheter employed in still another proposed technique
includes a tubular body that has an opening for ejection and an
opening for suction. To dissolve an object to be dissolved, a
dissolving agent is ejected out from the opening for ejection to
the object to be dissolved. Parts of the object to be dissolved may
remain un-dissolved. Such fine fragments of the object to be
dissolved are sucked into the tubular body from the opening for
suction. In addition, mechanical means for generating vibrations is
provided to the tubular body so as to fracture the object to be
dissolved. With the suction catheter described above, fine
fragments of a blood clot that has been fractured and left
undissolved are sucked into the tubular body from the opening for
suction. For more detail, see Japanese Patent Application
Publication No. 2006-263125 (Patent Document 4).
A suction catheter employed in still another proposed technique is
provided with a vibrator. An irregular-surface portion is formed in
the outer circumferential surface of the leading-end portion of the
suction catheter. The vibrator makes the irregular-surface portion
vibrate, and the vibrating irregular-surface portion chips away the
atheroma formed in the arteriosclerotic narrowed lesion. The
chipped fragments of the atheroma is sucked from the opening
portion for suction at the leading-end portion of the catheter, and
taken out of the body. For more detail, see Japanese Patent
Application Publication No. 2000-279525 (Patent Document 5).
Neither the means disclosed in Patent Document 1 nor the means
disclosed in Patent Document 2 has an enough ability to easily and
smoothly remove a blood clot. Likewise, the product with an
obliquely-formed leading-end portion does not have an enough
ability to easily and smoothly remove a blood clot.
In all of the means disclosed in Patent Documents 3 to 5, the
position where the blood clot is subjected to fracturing or the
like is away from the position where the blood clot is to be
retrieved. For this reason, when the direction of blood flow is not
favorable, the fragments of the blood clot may possibly flow away
down the stream. For example, when a blood clot is removed from a
blood vessel located in the head, the catheter has to be inserted
from the upstream side of the blood clot in the direction of blood
flow. Accordingly, the fragments of the blood clot readily flow
away down the stream unless the fragments of the blood clot are
retrieved substantially at the same time of the fracturing or the
like. When the original blood clot is formed in an arterial system,
the fragments of the blood clot that have flowed down the stream
may cause a new blood clot to be formed in a peripheral
capillary.
The description given thus far reveals some of the requirements for
a suction catheter used for sucking and removing an object, such as
a blood clot, formed inside a blood vessel. What follows are some
examples of such requirements.
1) To have an enough ability to remove the blood clot.
2) To be capable of preventing the blood-clot fragments from
flowing down the stream.
3) To allow the cutting and the suction of the blood clot to be
carried out safely.
4) To follow the complex bending of the blood vessel.
None of the suction catheters that have been proposed thus far
satisfies all the above-mentioned requirements. Accordingly, what
has been longed for is a proposal for a suction catheter that is
capable of retrieving and removing, easily and smoothly, an object,
such as a blood clot, formed inside a blood vessel from the blood
vessel without allowing the flowing-away of the object down the
stream.
SUMMARY OF THE INVENTION
The above-described circumstances have led us to make the present
invention. Accordingly, an object of the present invention is to
provide a suction catheter that is capable of retrieving and
removing, easily and smoothly, an object, such as a blood clot,
formed inside a blood vessel from the blood vessel without allowing
the flowing-away of the object down the stream. Another object of
the present invention is to provide a suction-catheter system that
allows the above-mentioned suction catheter to operate
efficiently.
To achieve the above-mentioned objects, an aspect of the present
invention provides a suction catheter made of a flexible lengthy
body with a lumen formed in the flexible lengthy body, and used in
a treatment where a leading-end side of the suction catheter is
inserted into a blood vessel, where a base-end portion is connected
to a suction apparatus, and where the lumen is vacuumed by means of
the suction apparatus so as to suck out and retrieve an object in
the blood vessel. The provided suction catheter includes a catheter
main body, a leading-end case portion, and object cutting means.
The catheter main body is made of the lengthy body. The leading-end
case portion is positioned at a leading-end portion of the catheter
main body and includes an opening for retrieving the object. The
object cutting means is partially exposed through the opening, and
is movable in the axial direction within the leading-end case
portion. In addition, the object cutting means includes a cutting
portion and a power receiving portion. The cutting portion includes
a cutting area made of a wire-like member provided so as to
traverse in a substantially perpendicular direction to the axial
direction. The power receiving portion is connected to the cutting
portion and moves the cutting portion in the axial direction when
the power receiving portion receives power from outside. While the
object cutting means is in operation, the object that sticks to an
internal wall of the blood vessel is cut off, at the opening of the
leading-end case portion, by means of the cutting area of the
cutting portion.
In addition, it is preferable that, in the suction catheter, the
cutting portion be a spiral body formed by winding up the wire-like
member a number of times.
In addition, it is preferable that, in the suction catheter, the
leading-end case portion include a locking stopper formed in an
internal wall of the leading-end case portion. The locking stopper
is designed to restrict a movement of the object cutting means
toward the base-end portion of the catheter main body.
In addition, it is preferable that, in the suction catheter, either
at least a part of the leading-end case portion or at least a part
of the object cutting means be made of a metal member.
In addition, it is preferable that, in the suction catheter, the
opening be formed in a leading-end inclined face of an
obliquely-formed leading-end portion of the leading-end case
portion.
In addition, it is preferable that, in the suction catheter, the
opening be formed in a leading-end-side circumferential-body
surface of the leading-end case portion.
In addition, it is preferable that, in the suction catheter, the
power receiving portion be made of a magnetic material, and that
the leading-end case portion includes magnetic-force generating
means for supplying power to the power receiving portion. The
magnetic-force generating means is provided to the internal wall of
the leading-end case portion.
In addition, it is preferable that, in the suction catheter, at
least one of the catheter main body and the leading-end case
portion includes a guide-wire hole formed in the outer surface
thereof. The guide-wire hole allows a guide wire to be inserted
thereinto.
In addition, another aspect of the present invention provides a
suction-catheter system that includes: the above-described suction
catheter; and driving means for supplying power to the object
cutting means included in the suction catheter.
In addition, it is preferable that, in the suction catheter system,
the driving means be capable of adjusting the strength of the power
supplied to the object cutting means.
In addition, it is preferable that, in the suction catheter system,
the object cutting means include a stretchable member that enables
the object cutting means to move back and forth in response to the
change in the strength of the power supplied by the driving means,
and that the driving means be a suction apparatus that attracts the
object cutting means by means of a sucking force.
In addition, it is preferable that, in the suction catheter system,
at least a part of the object cutting means be made of a magnetic
material, and that the driving means be a magnetic-force apparatus
that attracts or repels the object cutting means by means of a
magnetic force.
In the suction catheter provided according to the aspects of the
present invention, the leading-end case portion with an opening for
retrieving an object in a blood vessel is positioned at the
leading-end portion of the catheter main body that is made of a
flexible lengthy body with a lumen formed therein. The suction
catheter includes the object cutting means that is partially
exposed through the opening and is movable, within the leading-end
case portion, in the same direction as the direction of the
longitudinal axis of the catheter main body. Accordingly, the
position where the object is cut off by means of the object cutting
means and the position of the opening where the object thus cut off
is retrieved within the blood vessel are not away from each other.
Rather, the suction catheter has a structure in which the
above-mentioned two positions can be made substantially the same.
Accordingly, the cutting operation, which is performed at the
opening of the leading-end case portion by means of the object
cutting means in operation, to cut the object sticking to the
internal wall of the blood vessel and the sucking operation to take
the cut-off object into the leading-end case portion from the
opening as quickly as possible can be processed in an almost
simultaneous parallel fashion.
For this reason, the aspects of the present invention can provides
a suction catheter that is capable of retrieving and removing,
easily and smoothly, an object, such as a blood clot, formed inside
a blood vessel from the blood vessel without allowing the
flowing-away of the object down the stream.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B are drawings each of which illustrates a suction
catheter according to a first embodiment of the present invention.
FIG. 1A is a schematic sectional view illustrating the suction
catheter before its cutting action. FIG. 1B is a schematic
sectional view illustrating the suction catheter after its cutting
action.
FIGS. 2A, 2B, and 2C are drawings illustrating a series of actions
of object cutting means of the suction catheter according to the
first embodiment of the present invention. FIG. 2A is a schematic
sectional view illustrating the state before a sucking force is
supplied. FIG. 2B is a schematic sectional view illustrating the
state where a strong sucking force is supplied. FIG. 2C is a
schematic sectional view illustrating the state where a weak
sucking force is supplied instead of the strong sucking force.
FIGS. 3A, 3B, and 3C are schematic sectional views illustrating a
series of steps for cutting and removing an object (a blood clot)
by means of a suction catheter according to the first embodiment of
the present invention. FIG. 3A is a schematic sectional view
illustrating the state where the suction catheter is inserted into
a blood vessel. FIG. 3B is a schematic sectional view illustrating
the state where a leading-end face of the suction catheter is
brought into contact with the blood clot. FIG. 3C is a schematic
sectional view illustrating the state where blood clot is cut by
means of the object cutting means and the resultant fragments of
the blood clot are retrieved.
FIGS. 4A and 4B are drawings each of which illustrates a retrieval
channel for the object (the blood clot) formed in the suction
catheter according to the first embodiment of the present
invention. FIG. 4A is a schematic sectional view illustrating the
state where the retrieval channel is fully opened. FIG. 4B is a
schematic sectional view illustrating the state where the retrieval
channel is partially closed with a power receiving portion of the
object cutting means.
FIG. 5 is a schematic sectional view illustrating a suction
catheter according to a second embodiment of the present
invention.
FIG. 6 is a schematic sectional view illustrating a suction
catheter according to a third embodiment of the present
invention.
FIG. 7 is a schematic sectional view illustrating a suction
catheter according to a fourth embodiment of the present
invention.
FIG. 8 is a schematic sectional view illustrating the state where
an object (a blood clot) is cut and removed by means of the suction
catheter according to the fourth embodiment shown in FIG. 7.
FIG. 9 is a schematic sectional view illustrating a suction
catheter according to a fifth embodiment of the present
invention.
FIG. 10 is a schematic sectional view illustrating the state where
an object (a blood clot) is cut and removed by means of the suction
catheter according to the fifth embodiment shown in FIG. 9.
FIG. 11 is a schematic sectional view illustrating a suction
catheter according to a sixth embodiment of the present
invention.
FIG. 12 is a schematic plan view illustrating object cutting means
of the suction catheter according to the sixth embodiment shown in
FIG. 11.
FIG. 13 is a schematic sectional view illustrating a conventional
suction catheter.
DETAILED DESCRIPTION OF THE INVENTION
Some exemplary embodiments of the present invention will be
described below with reference to the drawings.
Note that the embodiments described below are preferred specific
examples with various technical limitations. However, the
embodiments with such limitations are not the only forms
representing the scope of the present invention unless a specific
remark to the effect that the present invention is limited in a
described way is given in the following description.
A suction catheter to be provided according to the present
invention is assumed to be used in the following treatment. The
leading-end side of the suction catheter is inserted into a blood
vessel while the base-end portion of the suction catheter is
connected to a suction apparatus. The lumen is vacuumed by means of
this suction apparatus, so that the object inside the blood vessel
can be sucked out and retrieved.
To put it differently, the suction catheter of the present
invention is used together with suction means (a suction
apparatus). When an object causes an occluded blood-vascular
system, such as in the case of cerebral infarction or myocardial
infarction, the suction catheter is inserted deeply into the blood
vessel until the suction catheter can reach the lesion. An object,
such as a blood clot, that causes the occlusion of the blood vessel
(hereafter, such an object will be simply referred to as a "blood
clot") is sucked directly by the suction catheter, and is thus
removed out of the body. Note that the suction apparatus to be used
in the following embodiments is an ordinary suction apparatus that
is commonly used in the above-mentioned treatment. Accordingly, no
description of the suction apparatus will be given in the following
embodiments.
First Embodiment
FIGS. 1A and 1B are drawings each of which illustrates a suction
catheter according to the present invention. FIG. 1A is a schematic
sectional view illustrating the suction catheter before its action.
FIG. 1B is a schematic sectional view illustrating the suction
catheter after its action.
As FIGS. 1A and 1B show, a suction catheter 10 according to this
first embodiment includes: a catheter main body 1; a leading-end
case portion 2 positioned at a leading-end portion 1a of the
catheter main body 1; and object cutting means 3 installed in the
leading-end case portion 2.
The catheter main body 1 is a flexible lengthy body with a lumen 11
formed inside the main body. The catheter main body 1 with such a
structure is capable of following sufficiently the bending of the
blood vessel.
The catheter main body 1 can be made of various materials. Some
examples of such materials are: polyvinyl chloride; polyethylene;
polypropylene; polyurethane; ethylene-propylene copolymer;
ethylene-vinyl acetate copolymer; other polyolefins; polyethylene
terephthalate; polybutylene terephthalate; other polyesters;
polyamide; polyimide; polytetrafluoroethylene;
polyvinylidene-fluoride; other fluorinated resins; various other
thermoplastic resins; various other thermosetting resins; polyamide
elastomer; polyester elastomer; other thermoplastic elastomers; and
various rubbers.
The outer diameter of the catheter main body 1 is not limited to a
certain range. The outer diameter of the catheter main body 1 is
preferably made as small as possible in the interest of removing a
blood clot formed in a capillary. A preferable outer diameter of
the catheter main body 1 is, for example, approximately 1 mm.
An opening 4 is formed in the leading-end case portion 2, and the
blood clot is retrieved through the opening 4. The opening 4 also
serves as the inlet through which the blood clot is sucked into the
vacuumed lumen 11 of the catheter main body 1. Accordingly, the
opening 4 is formed so as to face the blood clot that sticks to the
internal wall of the blood vessel.
As FIGS. 1A and 1B show, the leading-end portion of the leading-end
case portion 2 is formed obliquely to be a leading-end inclined
face 21, and the opening 4 is formed in the leading-end inclined
face 21.
The leading-end case portion 2 may be formed either integrally with
or separately from the catheter main body 1.
A part of the object cutting means 3 is exposed through the opening
4. In addition, the object cutting means 3 is movable in the axial
direction within the leading-end case portion 2. Note that "the
axial direction" mentioned here is the same direction as the
direction of the longitudinal axis of the catheter main body 1.
The object cutting means 3 includes, for example, a cutting portion
31 that is exposed through the opening 4, and a power receiving
portion 32 which receives the power from outside and which moves
the cutting portion 31.
Accordingly, the use of the suction catheter 10 requires driving
means to give the power to the power receiving portion 32 of the
object cutting means 3. Combining the suction catheter 10 and the
driving means (not illustrated) together forms a suction catheter
system in the present invention.
The cutting portion 31 may be made of a wire-like member that is
provided so as to traverse in a substantially perpendicular
direction to the axial direction in which the object cutting means
3 is movable. The direction that is substantially perpendicular to
the movable direction for the object cutting means 3 can be
understood as follows. When moving along with the movement of the
object cutting means 3, the cutting portion 31 draws a plane
trajectory in the above-mentioned direction.
In addition, the cutting portion 31 is formed so as to have a
retrieving opening for readily taking the blood clot that has been
cut into the inside of the leading-end case portion 2.
Some examples of the cutting portion 31 formed by a wire-like
member with a retrieving opening are: an arch-shaped body with a
wire-like member with only one cutting region formed; and a spiral
body formed by winding up, a number of times, a wire-like member
with gaps between two adjacent lines so as to form plural cutting
areas. Note that the wire-like member portion is provided so as to
traverse in a substantially perpendicular direction to the axial
direction in which the object cutting means is movable.
Accordingly, when the cutting portion 31 is made of the arch-shaped
body and the spiral body, the wire-like member portion provided in
the above-mentioned way has an arc shape that resembles the shape
of the internal wall of the blood vessel. The cutting portion 31
with the above-described form can remove efficiently the blood
clot.
In FIGS. 1A and 1B, the cutting portion 31 is illustrated as a
spiral-shaped body (coil-spring shape). The spiral-shaped cutting
portion 31 has a first end 31a fixed to the proximity of an
internal leading end 2a of the leading-end case portion 2, and a
second end 31b provided with the power receiving portion 32.
An example of an external power to move the power receiving portion
32 is the sucking force to attract the power receiving portion 32.
The use of sucking force as the power used for the above-mentioned
purpose allows a suction apparatus (not illustrated) used for
vacuuming the lumen 11 of the catheter main body 1 and for sucking
and retrieving the blood clot to be also used as the source of
sucking force. Accordingly, no additional driving means for giving
power needs to be provided, so that the fracturing of and the
retrieving of the blood clot can be carried out economically and
with efficiency both in design and in operation.
Incidentally, the use of the sucking force as the power to attract
the power receiving portion 32 allows the power receiving portion
32 to be formed as a spherical voluminous portion attached to the
second end of the spiral-shaped cutting portion 31.
Now, suppose a case where the suction apparatus (not illustrated)
is used for vacuuming the lumen 11 of the catheter main body 1 of
the suction catheter 10 of this embodiment shown in FIG. 1A. In
this case, a sucking force indicated by the outline arrow in FIG.
1B is produced. Accordingly, the power receiving portion 32 is
supplied with a power, and moves in the direction indicated by the
solid-line arrow. In addition, along with the movement of the power
receiving portion 32, the cutting portion 31 stretches out in the
direction indicated by the dot-line arrow so as to widen the
distances between adjacent sections of the wire-like member of the
cutting portion 31.
In addition, when the cutting portion 31 is formed as a spiral body
in this embodiment, the spring elastic force of the cutting portion
31 allows the object cutting means 3 to move back and forth as
FIGS. 2A, 2B, and 2C show. FIGS. 2A, 2B, and 2C are drawings
illustrating a series of actions of the object cutting means 3 in
the suction catheter 10.
The back-and-forth motion of the object cutting means 3 can be
achieved by adjusting the strength of the power in the driving
means for giving power to the power receiving means 32. In this
embodiment, the power strength is adjusted by making the sucking
pressure stronger or weaker.
To be more specific, while the driving means (not illustrated) is
not in operation, the suction catheter 10 stays in a state where
the cutting portion 31 is contracted toward the internal leading
end 2a of the leading-end case portion 2 as FIG. 2A shows.
When the driving means give a strong sucking force to the power
receiving portion 32, the power receiving portion 32 is pulled
toward the side of the base-end portion of the catheter main body
1, and the cutting portion 31 stretches out along with the movement
of the power receiving portion 32 as FIG. 2B shows.
When the driving means stops its operation or when the sucking
force of the driving means is weakened, the power receiving portion
32 is pulled back to the side of the internal leading end 2a of the
leading-end case portion 2 by the spring biasing force that is
inherent in the cutting portion 31. This is the state that FIG. 2C
shows.
Note that what makes the back-and-forth motion of the object
cutting means 3 possible in this embodiment is the spring elastic
force inherent in the cutting portion 31 that is formed as a spiral
body. In contrast, when the object cutting means is not
stretchable, a separate stretcher portion has to be provided.
As FIGS. 1A and 1B, and 2A to 2C show, locking stoppers 5 and 5 are
formed in the internal wall of the leading-end case portion 2 in
this embodiment. The locking stoppers 5 and 5 are designed to
restrict the movement of the power receiving portion 32 toward the
side of the base-end portion of the catheter main body 1. The
locking stoppers 5 and 5 prevent the power receiving portion 32
from being pulled an unnecessarily long distance, so that an
efficient and smooth back-and-forth motion of the object cutting
means 3 can be achieved.
Note that the locking stoppers 5 and 5 may be formed integrally
with the leading-end case portion 2 or may be formed separately
from the leading-end case portion 2 and attached thereto.
What will be described next is a way of cutting and removing a
blood clot in a blood vessel by means of the suction catheter 10
with the above-described configuration. FIGS. 3A, 3B, and 3C are
schematic sectional diagrams illustrating a series of steps for
cutting and removing a blood clot by means of a suction
catheter.
Firstly, as FIG. 3A shows, the suction catheter 10 is inserted into
a blood vessel BV until a leading-end side 10a of the suction
catheter 10 reaches a blood clot BC. In the meanwhile, the base-end
portion of the suction catheter 10 is connected to a suction
apparatus.
Then, as FIG. 3B shows, the cutting portion 31 of the object
cutting means 3 exposed through the opening 4 of the leading-end
case portion 2 is brought into contact with the blood clot BC.
Subsequently, as FIG. 3C shows, the lumen 11 is vacuumed by means
of the suction apparatus, and the object cutting means 3 is made to
move back and forth. The blood clot BC in the blood vessel BV is
thus cut by the cutting portion 31, and the fragments of the blood
clot BC are securely sucked in, and caught, and then are retrieved.
FIG. 3C shows how five fragments bc1, bc2, bc3, bc4, and bc5 that
are cut from the blood clot BC are sucked and retrieved.
In addition, as FIG. 4A shows, the plural bump-shaped locking
stoppers 5 and 5 are formed so as to protrude from some parts of
the internal wall surface of the leading-end case portion 2. The
rest of the leading-end case portion 2 serves as a retrieval
channel 6 used when the fragments of the blood clot BC are sucked
and retrieved. Now, suppose a case where a single annular locking
stopper 5 is formed with a uniform height (thickness) all along the
circumference of the internal wall of the leading-end case portion
2. In this case, when the power receiving portion 32 pulled toward
the base-end portion side of the catheter main body 1 is brought
into contact with the locking stopper 5, the power receiving
portion 32 may possibly close the retrieval channel 6.
To avoid such an inconvenience, the plural bump-shaped locking
stoppers 5 and 5 are formed so as to protrude from some parts of
the internal wall surface of the leading-end case portion 2.
Accordingly, as FIG. 4B shows, even when the power receiving
portion 32 pulled toward the base-end portion side of the catheter
main body 1 is brought into contact with the locking stoppers 5 and
5, the retrieval channel 6 is not closed completely. Part of the
retrieval channel 6 corresponding to the outside of the power
receiving portion 32 is left unclosed. For this reason, the
fragments of the blood clot BC can be securely sucked and retrieved
through the retrieval passage 6.
Besides, it is preferable that, in this embodiment, at least a part
of the leading-end case portion 2 or at least a part of the object
cutting means 3 be made of a metal member. Such a use of metal
makes the position of the leading end of the catheter main body 1
observable by means of an X-ray image.
As has been described thus far, the blood clot BC is cut, in this
embodiment, by means of the cutting portion 31 of the object
cutting means 3 exposed through the opening 4 formed in the
leading-end case portion 2. In this event, when the opening 4 is
brought into contact with the blood clot BC at the beginning of the
cutting operation, the blood clot BC is pulled into the leading-end
case portion 2 through the opening 4 by the negative pressure
produced in the lumen 11. In addition, the power receiving portion
32 is pulled toward the side of the base-end portion of the
catheter main body 1 by the negative pressure produced in the lumen
11, and the cutting portion 31 is stretched out. The cutting
portion 31 thus stretched out cuts the blood clot BC, and the
fragment of the cut blood clot BC are immediately sucked into the
leading-end case portion 2, by the negative pressure produced in
the lumen 11, through the opening 4 and the retrieving opening that
is a gap formed in the cutting portion 31.
Accordingly, the blood clot BC can be retrieved and removed easily
and smoothly from the blood vessel BV while all the fragments of
the cut blood clot BC are sucked into the leading-end case portion
2 without allowing any of the fragments to flow away. In addition,
the cutting portion 31 cuts only a part of the blood clot BC
corresponding to the cutting portion 31 of the object cutting means
3 exposed through the opening 4. Accordingly, the cutting and the
suction of the blood clot BC can be carried out safely without
damaging the other parts, such as the internal wall of the blood
vessel BV.
In addition, the object cutting means 3 (the cutting portion 31) in
this embodiment is made to move back and forth by adjusting the
sucking force produced by the driving means. When the strong
negative pressure in the lumen 11 is made weaker, the restoring
force of the spring elasticity inherent in the cutting portion 31
contracts the cutting portion 31 back to its original length. While
the cutting portion 31 is restoring the original length, the
cutting portion 31 cuts the blood clot BC. The fragments of the
blood clot BC thus cut out are immediately sucked, by the negative
pressure produced in the lumen 11, into the leading-end case
portion 2 through the opening 4 and the retrieving opening that is
a gap formed in the cutting portion 31.
Accordingly, the blood clot BC can be cut and removed efficiently
by the repeating of the back-and-forth motion including an action
for the stretching-out of the cutting portion 31 and an action for
the contracting of the cutting portion 31 until the restoration of
its original length. In addition, the opening 4 is formed in the
leading-end inclined face 21, which is the obliquely-formed
leading-end portion of the leading-end case portion 2. Accordingly,
even when the circumferential body portion of the suction catheter
10 cannot be inserted so as to face the blood clot BC, the cutting
and the removing of the blood clot BC can be carried out, little by
little, starting from the edge portion of the blood clot BC.
Second Embodiment
The suction catheter of the present invention can be modified for
the purpose of allowing the suction catheter to be efficiently
inserted into the blood vessel and of allowing the leading end of
the suction catheter to reach the lesion (the blood clot) easily.
To put it differently, a suction catheter of this second embodiment
differs from the suction catheter of the above-described first
embodiment in that the suction catheter of the second embodiment is
provided with means for assisting the insertion of suction
catheter.
Incidentally, when each of the following embodiments is described,
the description to be given focuses mainly on the points that
differ between each of the following embodiments and the
above-described first embodiment. For those constituent parts that
are common to each of the following embodiments and the
above-described first embodiment, the same reference numerals that
are used in the first embodiment will be given in each of the
following embodiments. No description will be given for those
common constituent parts. To put it differently, those constituent
parts that will not be described specifically in the following
embodiments can be assumed to be the same as those counterparts
described in the first embodiment.
As FIG. 5 shows, a suction catheter 20 according to this second
embodiment includes: a catheter main body 1; a leading-end case
portion 2 positioned at a leading-end portion 1a of the catheter
main body 1; and object cutting means 3 installed in the
leading-end case portion 2. In addition, a guide-wire hole 7 is
formed in the outer surface of at least one of the catheter main
body 1 and the leading-end case portion 2. A guide wire W is
inserted into the guide-wire hole 7. The suction catheter 20 is
provided with the guide-wire hole 7 that serves as means for
assisting the insertion of suction catheter and that formed along
the longitudinal-axis direction of the suction catheter 20.
As has been described above, in this embodiment, the guide wire W
that has been beforehand placed in the blood vessel is inserted
into the guide-wire hole 7, and the suction catheter 20 is inserted
along the guide wire W. The guide-wire hole 7 is thus used as the
means for assisting the insertion of suction catheter. Accordingly,
the suction catheter 20 can be efficiently inserted into the blood
vessel.
Third Embodiment
The suction catheter of the present invention can be modified for
the purpose of allowing the driving means to give the power that is
not the sucking force to the object cutting means. To put it
differently, a suction catheter of this third embodiment differs
from the suction catheter of the above-described first embodiment
in that the suction catheter of this third embodiment is provided
with driving means that is not a suction apparatus.
As FIG. 6 shows, a suction catheter 30 according to this third
embodiment includes: a catheter main body 1; a leading-end case
portion 2 positioned at a leading-end portion 1a of the catheter
main body 1; and object cutting means 13 installed in the
leading-end case portion 2.
The object cutting means 13 is made, either partially or entirely,
of a magnetic material, and includes, for example, a cutting
portion 31 exposed through an opening 4 and a power receiving
portion 33. The power receiving portion 33 moves the cutting
portion 31 when a magnetic force is applied to the power receiving
portion 33 from outside.
The power receiving portion 33 may be made of a permanent magnet.
The permanent magnet used for this purpose may be a ferrite magnet
or a rare-earth magnet. In other words, a permanent magnet of any
kind may be used for this purpose.
The driving means of this third embodiment is a magnetic-force
apparatus that is capable of attracting or repelling the power
receiving portion 33 by means of the magnetic force.
An example of the magnetic apparatus is an apparatus including an
electromagnet 35 provided to the internal wall of the leading-end
case portion 2 and a power-supply source that supplies electricity
to the electromagnet 35 via an electric wire 36. The electromagnet
35 is capable of generating a magnetic force temporarily when
energized. The electromagnet 35 is also capable of reverse the
magnetic polarities when the direction of the electric current
supplied to the electromagnet 35 is reversed.
As has been described above, in this embodiment, the magnetic force
(attractive magnetic field) generated by the energized
electromagnet 35 attracts the power receiving portion 33 to the
electromagnet 35. When the electromagnet 35 ceases to be energized,
the magnetic force also ceases to be generated, and the object
cutting means 13 is made to be attracted to an internal leading end
2a of the leading-end case portion 2 by the spring biasing force
inherent in the cutting portion 31. In this way, the power is given
to the object cutting means 13 in this third embodiment.
Alternatively, the power can be given to the object cutting means
13 by attracting the power receiving portion 33 to the
electromagnet 35 and by repelling the power receiving portion 33
from the electromagnet 35 while the polarity of the electromagnet
35, that is, the direction of the electric current applied for
energizing the electromagnet 35 is repeatedly reversed. To put it
differently, the power can be given to the object cutting means 13
by the generation of an attractive magnetic field and a repulsive
magnetic field, which is accomplished by reversing the direction of
the electric current applied to the electromagnet 35.
Accordingly, the suction catheter 30 of this third embodiment is
capable of moving the object cutting means 13 back and forth
without weakening the sucking force used for retrieving the
fragments of the blood clot.
Fourth Embodiment
The suction catheter of the present invention can be modified for
the purpose of allowing the opening that is to be brought into
contact with the blood clot to face in a different direction. To
put it differently, a suction catheter of this fourth embodiment
differs from the suction catheter of the above-described first
embodiment in that the opening of this fourth embodiment is formed
at a position that is different from the position of its
counterpart of the first embodiment.
As FIG. 7 shows, a suction catheter 40 according to this fourth
embodiment includes: a catheter main body 1; a leading-end case
portion 12 positioned at a leading-end portion 1a of the catheter
main body 1; and object cutting means 3 installed in the
leading-end case portion 12.
Plural openings 14 and 14 to retrieve the blood clot are formed in
the leading-end case portion 12. The openings 14 and 14 also serve
as the inlets through which the blood clot is sucked into the
vacuumed lumen 11 of the catheter main body 1. Accordingly, each of
the openings 14 and 14 is formed so as to face the blood clot that
sticks to the internal wall of the blood vessel.
As FIGS. 7 shows, the leading-end case portion 12 has a conical
surface 41 that is formed so as to gradually reduce its diameter
toward the leading end of the leading-end case portion 12, and the
openings 14 and 14 are formed in the conical surface 41. Note that
the conical surface mentioned here may be a surface formed so as to
uniformly reduce its diameter toward the leading end of the
leading-end case portion 12, or may be an arc-shaped surface formed
so as to reduce its diameter with a degree of reduction increasing
toward the leading end of the leading-end case portion 12.
The leading-end case portion 12 may be formed either integrally
with or separately from the catheter main body 1.
Parts of the object cutting means 3 are exposed through the
openings 14 and 14, respectively. In addition, the object cutting
means 3 is movable in the axial direction within the leading-end
case portion 12.
The object cutting means 3 includes, for example, a cutting portion
31 that is exposed through the openings 14 and 14, and a power
receiving portion 32 which receives the power from outside and
which moves the cutting portion 31.
In FIG. 7, the cutting portion 31 is illustrated as a spiral-shaped
body (coil-spring shape). The spiral-shaped cutting portion 31 has
a first end 31a fixed to the proximity of an internal leading end
12a of the leading-end case portion 12, and a second end 31b
provided with the power receiving portion 32.
What will be described next is a way of cutting and removing a
blood clot in a blood vessel by means of the suction catheter 40
with the above-described configuration. FIG. 8 is a schematic
sectional diagram illustrating a way of cutting and removing a
blood clot by means of a suction catheter.
Firstly, as FIG. 8 shows, the suction catheter 40 is inserted into
a blood vessel BV until a leading-end side 40a of the suction
catheter 40 reaches the position of a blood clot BC. Then, the
cutting portion 31 of the object cutting means 3 exposed through
the openings 14 and 14 of the leading-end case portion 12 is
brought into contact with the blood clot BC. In the meanwhile, the
base-end portion of the suction catheter 40 is connected to a
suction apparatus. Subsequently, the lumen 11 is vacuumed by means
of the suction apparatus, and the object cutting means 3 is made to
move back and forth. The blood clot BC in the blood vessel BV can
thus be cut by the cutting portion 31, and the fragments of the
blood clot BC can be sucked in and then retrieved.
As has been described thus far, in this fourth embodiment, the
plural openings 14 and 14 are formed in the conical surface 41 of
the leading-end case portion 12 formed so as to gradually reduce
its diameter toward the leading end. Accordingly, the suction
catheter 40 of this fourth embodiment can be placed so as to face
the blood clot BC formed in the blood vessel BV and sticking to the
internal wall of the blood vessel BV in every direction. In
addition, the cutting and the removing of the blood clot BC thus
formed and sticking to the internal wall in every direction can be
carried out without turning the suction catheter 40 that has been
placed in the blood vessel BV. Accordingly, the use of the suction
catheter 40 of this fourth embodiment eliminates the possibility of
harming the inside of the blood vessel BV with the turning action
that would be necessary otherwise.
Fifth Embodiment
The suction catheter of the present invention can be modified for
the purpose of allowing the opening that is to be brought into
contact with the blood clot to face in a still different direction.
To put it differently, a suction catheter of this fifth embodiment
differs from the suction catheters of the above-described first and
the fourth embodiments in that the opening of this fifth embodiment
is formed at a position that is different from the position of its
counterpart of any of the first and the fourth embodiments.
As FIG. 9 shows, a suction catheter 50 according to this fifth
embodiment includes: a catheter main body 1; a leading-end case
portion 22 positioned at a leading-end portion 1a of the catheter
main body 1; and object cutting means 3 installed in the
leading-end case portion 22.
An opening 24 is formed in the leading-end case portion 22, and the
blood clot is retrieved through the opening 24. The opening 24 also
serves as the inlet through which the blood clot is sucked into a
vacuumed lumen 11 of the catheter main body 1. Accordingly, the
opening 24 is formed so as to face the blood clot that sticks to
the internal wall of the blood vessel.
As FIG. 9 shows, an end portion of the leading-end case portion 22
is formed in a cylindrical shape to be a leading-end-side
circumferential-body surface 51, and the opening 24 is formed in
the leading-end-side circumferential-body surface 51.
The leading-end case portion 22 may be formed either integrally
with or separately from the catheter main body 1.
A part of the object cutting means 3 is exposed through the opening
24. In addition, the object cutting means 3 is movable in the axial
direction within the leading-end case portion 22.
The object cutting means 3 includes, for example, a cutting portion
31 that is exposed through the opening 24, and a power receiving
portion 32 which receives the power from outside and which moves
the cutting portion 31.
In FIG. 9, the cutting portion 31 is illustrated as a spiral-shaped
body (coil-spring shape). The spiral-shaped cutting portion 31 has
a first end 31a fixed to the proximity of an internal end 22a of
the leading-end case portion 22, and a second end 31b provided with
the power receiving portion 32.
What will be described next is a way of cutting and removing a
blood clot in a blood vessel by means of the suction catheter 50
with the above-described configuration. FIG. 10 is a schematic
sectional diagram illustrating a way of cutting and removing a
blood clot by means of a suction catheter.
Firstly, as FIG. 10 shows, the suction catheter 50 is inserted into
a blood vessel BV until a leading-end side 50a of the suction
catheter 50 reaches the position of a blood clot BC. Then, the
cutting portion 31 of the object cutting means 3 exposed through
the opening 24 of the leading-end case portion 22 is brought into
contact with the blood clot BC. In the meanwhile, the base-end
portion of the suction catheter 50 is connected to a suction
apparatus. Subsequently, the lumen 11 is vacuumed by means of the
suction apparatus, and the object cutting means 3 is made to move
back and forth. The blood clot BC in the blood vessel BV can thus
be cut by the cutting portion 31, and the fragments of the blood
clot BC can be sucked in and then retrieved.
As has been described thus far, in this fifth embodiment, the
opening 24 is formed in the cylindrical-shaped leading-end-side
circumferential-body surface 51 of the leading-end case portion 22.
Accordingly, the suction catheter 50 of this fifth embodiment can
be placed parallel with the wall surface of the blood vessel BV.
Accordingly, the cutting and removing of the blood clot can be
progressed from the inner side of the blood vessel BV towards the
wall surface of the blood vessel BV.
Sixth Embodiment
The suction catheter of the present invention can employ other
types of object cutting means. To put it differently, a suction
catheter of this sixth embodiment differs from the suction catheter
of the above-described first embodiment in the structure of the
object cutting means of the suction catheter.
As FIG. 11 shows, a suction catheter 60 according to this sixth
embodiment includes: a catheter main body 1; a leading-end case
portion 2 positioned at a leading-end portion 1a of the catheter
main body 1; and object cutting means 23 installed in the
leading-end case portion 2.
An opening 4 is formed in the leading-end case portion 2, and the
blood clot is retrieved through the opening 4. The opening 4 also
serves as the inlet through which the blood clot is sucked into the
vacuumed lumen 11 of the catheter main body 1. Accordingly, the
opening 4 is formed so as to face the blood clot that sticks to the
internal wall of the blood vessel.
As FIG. 11 shows, the leading-end portion of the leading-end case
portion 2 is formed obliquely to be a leading-end inclined face 21,
and the opening 4 is formed in the leading-end inclined face
21.
The leading-end case portion 2 may be formed either integrally with
or separately from the catheter main body 1.
A part of the object cutting means 23 is exposed through the
opening 4. In addition, the object cutting means 23 is movable in
the axial direction within the leading-end case portion 2. Note
that "the axial direction" mentioned here is the same direction as
the direction of the longitudinal axis of the catheter main body
1.
The object cutting means 23 includes, for example, a plate-shaped
cutting portion 37 that is exposed through the opening 4, and a
power receiving portion 32 which receives the power from outside
and which moves the plate-shaped cutting portion 37.
The plate-shaped cutting portion 37 includes two kinds of
protruding pieces 38a and 38a as well as 38b and 38b. The
protruding pieces 38a and 38a as well as 38b and 38b are raised up
in directions toward the side where the opening 4 is placed. The
plate-shaped cutting portion 37 also includes retrieving openings
39 and 39. The fragments of the blood clot cut off by the
protruding pieces 38a and 38a as well as 38b and 38b are taken into
the inside of the leading-end case portion 2 through the retrieving
openings 39 and 39. The plate-shaped cutting portion 37 can be
formed in a grater shape. For example, as FIG. 12 shows, plural
cuts each of which has a tongue shape are, firstly, made in the
surface of a plate-shaped member. Then, the portions of the cuts
thus made are raised up in directions toward the side where the
opening 4 is placed. Thus, plural pairs of a retrieving opening 39
and either a protruding piece 38a or a protruding piece 38b can be
formed while each the retrieving openings 39 is formed at the base
of the corresponding one of the protruding pieces 38a and 38a as
well as 38b and 38b.
Of the two kinds of protruding pieces 38a and 38a as well as 38b
and 38b, the first protruding pieces 38a and 38a work when the
object cutting means 23 moves from the leading-end side to the
rear-end side of the leading-end case portion 2. In contrast, the
second protruding pieces 38b and 38b work when the object cutting
means 23 moves from the rear-end side to the leading-end side of
the leading-end case portion 2 so as to restore the original
position.
FIG. 11 shows that the plate-shaped cutting portion 37 has a first
end 37a connected to a stretchable member 8 that is fixed to the
proximity of an internal leading end 2a of the leading-end case
portion 2. FIG. 11 also shows that the power receiving portion 32
is provided at a second end 37b of the plate-shaped cutting portion
37. The stretchable member 8 has a stretching function to allow the
object cutting means 23 to move back and forth.
As has been described thus far, the blood clot BC is cut, in this
sixth embodiment, by means of the plate-shaped cutting portion 37
of the object cutting means 23 exposed through the opening 4 formed
in the leading-end case portion 2. Accordingly, the blood clot BC
can be fractured into fine fragments of the blood clot BC, and then
removed. The fragments thus removed can be efficiently retrieved by
being sucked into the leading-end case portion 2 through the
opening 4.
The present invention is industrially useful in an industry that
employs suction catheters used, in a treatment, by being inserted
into a blood vessel for the purpose of sucking and removing an
object, such as a blood clot. The present invention is particularly
important in the market of suction catheters used for sucking and
removing a blood clot formed in the arteries of the brain or of the
heart as well as in the arteries and the veins of the four
limbs.
* * * * *